Hypotension

Hypotension is low blood pressure. A person with low blood pressure is called hypotensive.

Everybody's blood pressure is different. Some people have naturally low blood pressure. However, for most adults, a systolic blood pressure of under 90, or a diastolic blood pressure of under 60, is low blood pressure.[1] (Systolic is the top number in a blood pressure reading; diastolic is the bottom number.)

If the blood pressure gets even lower, or the person faints, when they stand up (this is called orthostasis or orthostatic hypotension). This means that the blood pressure is so low that it cannot get blood to the brain when the person is standing up.

Pale, cold, clammy skin (this is called diaphoresis). This is a sign that the body is in trouble, and is using its natural defense strategies to try to fix a problem.

Feeling very thirsty (this happens when low blood pressure is caused by dehydration, meaning the person has not drunk enough fluids. The body senses this and gets thirsty so the person will drink more)

Quick, shallow breathing (this is a sign that the body is not getting enough blood and oxygen, and is trying to take in more oxygen by breathing faster)

If low blood pressure makes a person faint, the person could hurt themselves while falling.[2]

If a person's blood pressure is very low, the heart will be unable to pump blood and oxygen to important parts of the body. Every part of the body needs blood and oxygen to live. Without blood and oxygen, important parts of the body, like the heart and brain, can be damaged.[1]

If a person's blood pressure is low enough that they are feeling dizzy, they should lay down on the ground. Putting their feet up, or bending their knees, is also helpful. This makes it easier for blood and oxygen to get to the brain (because the blood does not have to work against gravity to get up to the brain, like it would if the person were standing). Lying down will also make sure that the person does not hurt themselves by falling if they faint.[3]

Doctors can treat hypotension by treating whatever is causing the low blood pressure. Sometimes, low blood pressure is caused by dehydration. This can be treated by having the patient eat more salt, drink more fluids, or (in serious cases) get fluids through a needle placed into a vein.[2]

If low blood pressure is caused by medicines, doctors can change those medications to others that do not lower blood pressure as much.[3]

There are also medications that increase blood pressure. They work by making it harder for blood vessels to relax. (When blood vessels relax, blood pressure goes down. If the blood vessels cannot relax as easily, blood pressure goes up.)[3]